Devices for driving an oscillating auxiliary gripper of a printing press are widely known in the art. One embodiment of such a device is described, for example, in DE-PS No. 2,220,343. A disadvantage with this type of device is that non-positively cooperating drive elements are used to control the movement of the auxiliary gripper shaft. In operation a cam actuated in association with a spring presses a lever arm continuously onto a roller. Consequently, the non-positive elements are stressed very severely by the considerable mass forces which arise because of the high angular velocities and accelerations of the auxiliary gripper.
Another disadvantage is that control of the motion of the auxiliary gripper shaft calls for the use of input and output shafts whose center-axes are far apart from one another, leading to long linkages and, therefore, high mass forces. This consideration also applies to a camless drive of an oscillating auxiliary gripper such as is disclosed by EPA No. 0006402.
Other disadvantages are that the auxiliary gripper of such devices cannot be fully preassembled, and final assembly and replaceability are difficult as well.